Sadly enough, I have to admit that I've been sitting on 4-5 different projects that are almost ready for release but waiting for that 1 or 2 other "essential" feature to come of age. The problem I see, though, is that this is more of a debilitating issue for freelancers and single-developer shops than it is for organizations like Apple and Automattic.

If a single developer ships a buggy 1.0 release, they have to handle the outcry and support requests from the community while working on a more polished 2.0 (or even 1.1) update. If it's a team rather than an individual sharing the responsibility, you can isolate the developers from the support group and get things out the door while addressing the problems they cause at the same time.

So, while much of my hesitation to release in-development projects has been symptomatic of one-more-thing syndrome, nearly as much of it has also been symptomatic of I've-got-too-much-to-fix-and-not-enough-time-to-fix-it syndrome. You can only respond to so many support and feature requests and continue to maintain a solid development cycle ...